title: Prevalence of radiologic superior canal dehiscence in normal ears and ears with chronic otitis media.
abstract: OBJECTIVE
  Although labyrinth fistulae are caused mostly by cholesteatoma, they can occur in long-standing chronic otitis media (COM) without cholesteatoma. We aimed to compare the prevalence of radiologic SCD on computed tomography (CT) between normal ears and contralateral COM ears in patients with unilateral COM and to assess the prevalence of superior canal dehiscence (SCD) according to the age.
  
  
  METHODS
  Case series with comparison performed at a tertiary care academic referral center.
  
  
  METHODS
  We retrospectively reviewed consecutive temporal bone CT scans of 759 patients with unilateral COM between 2009 and 2011. The mean (± standard deviation) age was 48 years (±14 years). Images were independently evaluated by two otologists, and the bone overlying the superior canal was characterized as normal, suspicious, or definite SCD.
  
  
  RESULTS
  The prevalence (3.4%) of definite SCD in COM ears was significantly higher than that (0.3%) in normal ears. The prevalence (6.6%) of suspicious or definite SCD in COM ears was also higher than that (1.2%) in normal ears. There was no correlation between the prevalence of SCD and age in either normal or COM ears. All of the normal ears with suspicious or definite SCD also showed contralateral suspicious or definite SCD (bilateral involvement).
  
  
  CONCLUSIONS
  Our present findings suggest that the COM is related to the presence of SCD. The roof of the temporal bone may become thin by the failure of postnatal bone development and susceptible to chronic brain pulsation and pressure exerted by the temporal lobe in COM ears.
authors.affiliation: Department of Otolaryngology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
authors.forename: Young W
authors.initials: YW
authors.lastname: Cho
authors.forename: Byoung S
authors.initials: BS
authors.lastname: Shim
authors.forename: Ji W
authors.initials: JW
authors.lastname: Kim
authors.forename: Tae S
authors.initials: TS
authors.lastname: Kim
authors.forename: Joong H
authors.initials: JH
authors.lastname: Ahn
authors.forename: Jong W
authors.initials: JW
authors.lastname: Chung
authors.forename: Kwang-Sun
authors.initials: KS
authors.lastname: Lee
authors.forename: Tae H
authors.initials: TH
authors.lastname: Yoon
authors.forename: Hong J
authors.initials: HJ
authors.lastname: Park
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015984:Causality; D002908:Chronic Disease; D015897:Comorbidity; D005260:Female; D006801:Humans; D007759:Labyrinth Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010033:Otitis Media / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000503:physiopathology; D015995:Prevalence; D011379:Prognosis; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D012665:Semicircular Canals / Q000000981:diagnostic imaging* / Q000503:physiopathology; D017678:Sex Distribution; D013701:Temporal Bone / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Semicircular canals; chronic otitis media; computerized tomography; dehiscence; radiology